Method of circulating hot water through the pressure bags of tire retreading molds



June 4, 1935. H. J. woocK 0 ,5

METHOD OF CIRCULATING HOT WATER THROUGH THE PRESSURE BAGS OF TIRE RETREADING MOLDS Original Filed April 21, 1931 2 sheet s shet l INVENTOR. 2!

H. J. woocK METHOD OF CIRCULATING HOT WATER THROUGH THE June 4, 1935.

PRESSURE BAGS OF TIRE RETREADING MOLDS Original'Filed April 21, 1951 2 Sheets-Sheet \INVEN TOR. H J. W0 0 ch BY an) n-EL.

A TTORNEYS.

Patented June 4, 1935 UNITED STATES METHOD OF CIRCULATING HOT WATER THROUGH THE PRESSURE BAGS RETREADING MOLDS OF TIRE Herbert J. Woock, Lodi, Calif., assignor to Super Mold Corporation, Lodi, Calif., a corporation of N evada Original application. April 21, 1931, Serial No.

531,729. Divided and this application December 11, 1934, Serial No. 756,947

3 Claims. (or 18-53) showing the valve plug initsneutral position, or 1 I This invention relates to a method of circulating water heated to vul'canizing heat through the interior pressure bag of a tire retreading mold, preferably of the full circle type, such as shown in my Patent No. 1,764,378, dated June 17, 1930; and is particularly directed to the method of filling andretaining such inner pressure bag full of water heated to Vulcanizing temperature and under pressure.

This application is a division of my application Serial No. 531,729, filed April 21, 1931.

An object of the present invention is to provide a method for the purpose recited whereby there i is established a central supply of water and the water placed under a continuous gas pressure so that the water may be heated to vulcanizing temperature without turning into steam. Provision is then made to circulate. the thus heated water through the pressure bag while maintaining it under such pressure. This circulation under the conditions stated will be. maintained until vulcanization is complete when the water will be circulated back to the source of supply while still maintained under pressure and the gas will follow through into the pressure bag as the water is expelled. The heated water is'thus retained for further and repeated use when once broughtto vulcanizing'temperature so that there will be. no

I accomplish these objectsrpreferably by such structure and relative arrangement of parts and the use thereof in carrying out the steps of the method which accomplishes the results desired, all as will fully appear by a perusal ,of the following specification and claims.

In the drawings similar characters of reference indicate corresponding parts in the several views.

Figure 1 is a diagrammatic elevation of my improved circulating system.

Figure 2 is a sectional elevation of a six-wa valve preferably used 'to effect the centralized control of the system and showing the valve plug in its neutral position. 3 I

Figures 3-5 are cross sections of the valve taken on the lines 3-3, 4-4 and 55 respectively of Figure 2, and showing the valve plug in theiposition occupied when water is being circulated through the tire pressure bag.

Figures 6-8 are similar sectional viewsof the by air.

Figures 9-11 are similar sections of the valve when the water is merely being circulated between the pump and the tank.

Referring now more particularly to the. characters of reference on the drawings, the numeral I denotes one of the continuous circular sections of a retreading mold in which the tire 2 is mounted. The pressure bag '3 is placed. inside the tire which tire is engaged by arim 4 which prevents the sides of the tire from spreading and mold chambers is generated in the usual manner by an apparatus which has no relation with the present invention, and hence is not shown.

I will now describe in detail the water heating and circulating. system by which the water heated to vulcanizing heat is circulated through the presrelates. g The numeral 5 designates the steam generating boiler. A steam 00115 is arrangedin communication with the boiler so that a continuous circula tion of steam will be hadthrough the coil-as the same isgenerated in theboiler 5. A water tank 1- surrounds the coilso that water introduced-into this tank will beheated by transference of the heatfrom the steam moving throughthe coil;-

The water in the tank is maintained ata'constant temperature by providing an automatic thermostatic control device 8 connected to the tank and to the burner R of the boileri. v

A pipe 9 leads from a source of compressed gas such as air, located at a point remote from the system and is connected to the top of the tank I. The pressure in this pipe 9 is constant and is maintained at a pressure sufficient to preventthe water in the tank 1 from flashing into steam when it is heated to the high temperature necessary for vulcanization purposes.

The numeral 10 designates the casing of'a special six-way valvein which the valve plug ll is turnably mounted. A handle l2 applied to oneend of the plug controls its turning while a pawl this flange are spaced so that theplug may-be v10 also confines the bag in place. Steam to heat the held in any one of three predeterminedpositions.

The casing ID has opposed pairs of ports Aand D, Band E, C and F. The port A is connected tothe bag 3 at the bottom by a pipe l6; theport B is connected to the top of the tank 7 by a pipe l7; and the port C is connected to-the'bottom of the tank I by a pipe I8. The port D is connected by a pipe 20 to the discharge side of a circulating pump IS; the port E is connected to the bag 3 at the top by a pipe 2| while the port F is connected by a pipe 22 to the intake side of the pump I 9.

The plug l l is provided with a plurality of passages 23, 24 and 25 to register with ports A and D, B and E, and C and F respectively. 7 These are so arranged that upon turning the plug to a certain position the water may be fed into the bag 3 and circulated therethrough while being main-' tained at the predetermined pressure; This result is obtained as follows? The water may pass from the pipe l8 through the valve ports C and E and plug passage 25 and to the intake of the pump through the pipe 22, from the discharge side of the pumpthrough the pipe 20 back to the valve, and from the valve to the bag through the pipe It by means of ports.

A and D and plug passage 23. At the same time a return circulation of the water is had through the pipe 2|, the valve bymeans of ports E and B and the plug passage 24 and the pipe ll back to the top of the tank. The position of the plug in the valve body to give these results is shown in Figures 3, 4 and 5..

The air pressure fromrthe pipe!) being constantly on the water in the tank, the water in the pipes and pressure bag may be held at whatever pressure is desired. Bymeans of this pressure the water throughout the system, which is heated to a relatively high temperature by contact with the steam coil, is kept from turning into steam. During the period of circulation of the water from the tank 1 to and through the bag 3 and back to the tank 1; the .valve plug is left in the position described above in order to permit of the continuous circulation of the water, so heated through the pipe iB and leaves the valve through the pipe 22. This cycle is provided for by means of a by-pass 26 in the valve body leading from thepipe IE to a port G in said body in alinement with the plug passage 25 which then registers with said port G and the port F. The water then passes to the pump and circulates through the pipe 20 and then passes from the valve back to the tank through the pipe l8. This cycle is provided by means of another by-pass 21 in the valve body leading from a port H in the body in alinement with the plug passage 23 and extending to the pipe I8; the passage 23 then being positioned to place the ports D and H in communication.

As thewater is moved from the pressure bag back to the tank in the manner above described the compressed air or gas flows from the tank 1 and-follows up the receding water in the following manner:

Such air or gas leavesthe tank 1 through the pipe I? and passes through the valve into the top of the pressure bag 3 through the pipe 21 by way of ports B and E and-the plug passage 24.

It'will thus be seen that as the'bag 3 is completely emptied 'of'water, the water isreplaced by the compressed air so that the Water is maintained under its constant predetermined, pressure as it is returned to the tank I and is prevented froml flashing into. steam and, there is no ;wastage oi;

' so that it maybe keptup to proper vulcanizing temperature while the tire is being taken from the mold'and replaced by another.

To accomplish these steps the valve plug is moved to the positions shown in Figures 9, 10 and 11. This brings a by-pass 23 in the valve body leading from a port J in said body in alinement with the plug passage 23. to the pipe 11. The plug passage 23 then establishes communication between the ports D and J. The passage 24 then breaks com munication between the pipes H and 25 so that the air is shut ofi from passing back to the bag. The air then remaining in the bag can be exhausted to the atmosphere without the need of any other shut off valves at the bag connections. If it is not desired to circulate the water when it is not being passed to the pressure bag, it is only necessary of course to halt the operation of the pump when the parts are in the above positions.

The pipes l6 and 2! are provided with flexible connecting hoses. 25 by which connection is made with the inlet pipes 30 which lead into the top and bottom of the pressure bag for the purpose of turning out the circulation of the water and air as above described, which hoses and pipes are provided with any suitable means for connecting and disconnecting them, the particular construction of which is not essential to the invention herein disclosed, just so long as means is provided for properly admitting and withdrawing the circulating air and Water.

From the foregoing description of the mechanism by which my improved method. is carried out it will be apparent that the method per se comprises first, the step of establishing a source of water supply, placing this water supply under pressure with a gas to prevent the water when heated to vulcanizing temperature from flashing, into steam, and then heating the water to vulcanizing temperature. This source of water so heatedto vulcanizing temperature being established, the next step in the method is to. circulate the same continuously through the pressure bag while keeping it under the necessary pressure. This step is continued until vulcanization has taken place. When vulcanization is complete the next step then is to withdraw the water from the bag and return it to the source of supply while following it up with the gas under pressure so as to prevent the same from flashing into steam and to clear the bag and pipes of and heat which would necessarily be involved in case the water wasmerely circulated throughthe pressure bag and then withdrawn and discharged through a drain or other place without returning it to the source of supply for conservation and in readiness for repeated use.

It is to be understood that while I have specified water as being the liquid preferably used, other liquids such as oil, glycerine or the like are capable of being used instead. It is also to be understood that while I have shown and described the method of being capable of use in connection with a retreading mold, it is capable of being used with a tire making mold as well, or with a sectional repair mold.

From the foregoing description it will be readily seen that I have produced such a device as substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described my invention what I claim as new and useful and desire to secure by Letters Patent is:

1. That method of circulating hot water through a pressure bag comprising the steps of establishing a source of hot water, maintaining a gas pressure on the water to keep it liquid, circulating the water through thebag while maintaining the gas pressure, continuing such circulation for a desired length of time, discontinuing the circulation of the water through the bag, and returning the water to its source while still maintaining it under such gas pressure.

2. That method of circulating hot water.

through a pressure bag comprising the steps of establishing a source of hot water, establishing a source of gas under pressure and maintaining the gas under pressure against the water to keep the water liquid, circulating the water a desired length of time through the bag while maintaining the gas pressure against the same, discontinuing thecirculating of the water through the bag and returning the water to its source, replacing the water as it is withdrawn from the bag with the gas under pressure, and then breaking communication between the bag and both the source of water and gas.

3. That method of circulating hot water through a pressure bag comprising the steps of establishing a source of hot water, establishing a source of gas under pressure and maintaining the gas under pressure against the water to keep the water liquid, circulating the Water a desired length of time through the bag while maintaining the gas pressure against the same, discontinuing the circulating of the water through the bag and returning the water to its source, replacing the water as it is withdrawn from the bag with the gas under pressure, then breaking communication between the bag and both the source of water and gas, and then exhausting the gas from the bag.

HERBERT J. WOOCK. 

